Inclined drilling double-layer casing pipe and grouting pipe fixing method thereof

The invention provides an upward-inclined drilling double-layer sleeve which comprises an outer pipe, the outer pipe is hollow, the two ends of the outer pipe are open, a first cover plate is arranged at one end of the outer pipe, the upward-inclined drilling double-layer sleeve further comprises an inner pipe, the inner pipe is arranged in the outer pipe in a sleeved mode, the diameter of the outer pipe is set to be d1, the diameter of the inner pipe is set to be d2, d2 is smaller than d1, an annular space is formed between the inner pipe and the outer pipe, the axial length of the outer pipe is set to be S1, the axial length of the inner pipe is S2, and S1 is the axial length of the outer pipe; s2 is the axial length of the inner pipe; d1 is the diameter of the outer pipe; d2 is the diameter of the inner pipe; the end, close to the first cover plate, of the inner pipe is sleeved with the second cover plate, the first cover plate is connected with the second cover plate, grouting holes are formed in the pipe